Fine particulate matter (PM2.5) has been associated with a variety of problems that include adverse health effects, reduction in visibility, damage to buildings and crops, and possible interactions with climate. Although stringent air quality regulations are in place, policy makers need efficient tools to test a wide range of control strategies. Sensitivity analysis provides predictions on how the interdependent concentrations of various PM2.5 components and also gaseous pollutant species will respond to specific combinations of precursor emission reductions. The Community Multiscale Air Quality Model (CMAQ) was outfitted with the Decoupled Direct Method in 3D for calculating sensitivities of particulate matter (DDM-3D/PM). This method was evaluated and applied to high PM2.5 episodes in the Southeast United States. Sensitivities of directly emitted particles as well as those formed in the atmosphere through chemical and physical processing of emissions of gaseous precursors such as SO2, NOx, VOCs, and NH3 were calculated. DDM-3D/PM was further extended to calculate receptor oriented sensitivities or the Area of Influence (AOI). AOI analysis determines the geographical extent of relative air pollutant precursor contributions to pollutant levels at a specific receptor of interest. This method was applied to Atlanta and other major cities in Georgia. The tools developed here (DDM-3D/PM and AOI) provide valuable information to those charged with air quality management.

The high incidence of upper respiratory diseases, contamination of waterways due to pathogens and nutrients from human and animal wastes, unsustainable deforestation, gender disparities in burden of disease due to unequal exposure to indoor air pollutants, and carbon black emissions from the burning of solid fuels are interrelated problems in many developing countries. Small scale anaerobic digestion provides a means of alleviating these problems by treating livestock waste onsite to produce biogas (methane and carbon dioxide) in rural areas in developing countries. Fuel can then be used for cooking, lighting, and heating. Methane fuel is an alternative to traditional three-stone fires, improved cook stoves, and liquid petroleum gas. However, there is a lack of information available on design methods for these systems. The goal of this research was to develop a design tool that could be used for anaerobic digester sizing based on livestock waste availability. An Excel spreadsheet model was developed for sizing the bioreactor and the gas container based upon recommended values from a literature review. Needed monitoring parameters for operation of an anaerobic digester in the field were identified and standard methods of analysis were recommended. Sample preservation techniques were detailed. Guidelines for pathogen reduction in thermophilic anaerobic digestion were identified. Further study of pathogen reduction in low temperature reactors currently in use in developing countries was recommended. Three digester designs included in the Excel spreadsheet model were: the polyethylene tubular digester, the floating drum digester, and the fixed dome digester. The design tool may be requested from Dr. Sarina Ergas, sergas(at)usf.edu. An organic loading rate of 1.0 kg VS/(m3*d) was chosen for use in the design tool based upon a review of the literature. A semi-empirical kinetic model was developed for defining the SRT based on the temperature inputted by the user. Three case studies, based upon livestock waste availability in a rural community in the Dominican Republic, were analyzed using the sizing design tool. The case studies were conducted on three scales: one household, six households, and a village of 48 households. The specific biogas production rates were, for Case Studies one through three, respectively, 0.0076, 0.0069, and 0.010 m3 biogas/kg Volatile Solids reduced. Additional future work included: characterization of human feces and guinea pig manure, laboratory and field testing of the Excel spreadsheet design tool, and promotion of anaerobic digesters by development workers, non-governmental organizations, and governments.

The Particulate Matter Source Apportionment Technology (PSAT) is used together with PMCAMx, a regional chemical transport model, to estimate how local emissions and pollutant transport affect primary and secondary particulate matter concentration levels in European megacities such as Paris, London and Po Valley. The case of Paris megacity was investigated in detail. During the summer and the winter period examined, only 13% of the PM2.5 is due to local Paris emissions, with 36% due to mid range (within 500 km from the center of the Paris) sources and 51% resulting from long range transport (more than 500 km from the center of the Paris). The local emissions contribution to elemental carbon (EC) is significant, with almost 60% of the EC originating from local sources during both summer and winter. Approximately 50% of the fresh primary organic aerosol (POA) originated from local sources and another 45% from areas 100-500 km from the receptor region during summer. Regional sources dominated the secondary PM components. More than 70% of the sulfate originated from SO2 emitted more than 500 km away from the center of the Paris. Also more than 45% of secondary organic aerosol (SOA) was due to the oxidation of VOC precursors that were emitted 100-500 km from the center of the Paris. Long range sources are more important during winter because the photochemical activity is lower. PSAT results for contributions of local and regional sources were also compared with observation-based estimates from field campaigns that took place during the MEGAPOLI project. PSAT predictions are in general consistent with these estimates OA and sulfate but PSAT predicts lower transported EC for both seasons. / Ο καταμεριστικός αλγόριθμος ατμοσφαιρικών σωματιδίων (PSAT, Particulate Matter Source Apportionment Technology) χρησιμοποιείται σε συνδυασμό με το τρισδιάστατο μοντέλο χημικής μεταφοράς PMCAMx με σκοπό να εκτιμήσει κατά πόσο οι τοπικές εκπομπές και η μεταφορά της ρύπανσης επηρεάζουν τα πρωτογενή και τα δευτερογενή επίπεδα σωματιδιακών συγκεντρώσεων σε Ευρωπαϊκές μεγαλουπόλεις όπως το Παρίσι, το Λονδίνο και η κοιλάδα του ποταμού Πάδου στη βόρεια Ιταλία (Po Valley). Η περίπτωση του Παρισιού μελετήθηκε λεπτομερώς. Κατά τη διάρκεια του καλοκαιριού και του χειμώνα που εξετάστηκε, μόνο το 13% των PΜ2.5 σωματιδίων προέρχονται από τοπικές πηγές, 36% προέρχεται από ενδιάμεσες πηγές (μεταξύ 500 km από το κέντρο του Παρισιού) και 51% από απομακρυσμένες περιοχές (σε αποστάσεις μεγαλύτερες των 500 km από το κέντρο του Παρισιού). Η συνεισφορά των τοπικών πηγών στο στοιχειακό άνθρακα είναι σημαντική, 60% περίπου του στοιχειακού άνθρακα προέρχεται από τοπικές πηγές κατά τη διάρκεια τόσο του καλοκαιριού όσο και του χειμώνα. Σχεδόν 50% των φρέσκων πρωτογενών οργανικών σωματιδίων (POA) προέρχονται από τοπικές πηγές και 45% από περιοχές 100-500 km από των αποδέκτη κατά τη διάρκεια του καλοκαιριού. Οι συνεισφορά από απομακρυσμένες περιοχές κυριαρχεί στα δευτερογενή σωματίδια. Περισσότερο από 70% των θεϊκών σωματιδίων προέρχεται από διοξείδιο του θείου το οποίο εκπέμπεται από αποστάσεις μεγαλύτερες των 500 km από το κέντρο του Παρισιού. Επίσης περισσότερο από το 45% των δευτερογενών οργανικών σωματιδίων οφείλεται στην οξείδωση των πτητικών οργανικών ενώσεων (VOCs) που εκπέμπονται από 100 έως 500 km μακριά από το κέντρο του Παρισιού. Οι απομακρυσμένες περιοχές είναι πιο σημαντικές κατά τη διάρκεια του χειμώνα λόγω της ελάχιστης φωτοχημείας. Τα αποτελέσματα που προέκυψαν από τον αλγόριθμο PSAT για τις συνεισφορές των τοπικών όσο και των απομακρυσμένων περιοχών επίσης συγκρίνονται με μετρήσεις πεδίου από πειραματικές διατάξεις στο πλαίσιο του διεθνούς προγράμματος MEGAPOLI. Ο αλγόριθμος PSAT προβλέπει γενικά ικανοποιητικά τις συνεισφορές σε σχέση με αυτές που υπολογίστηκαν από τις μετρήσεις πεδίου.

A gasoline direct injection engine was set-up to operate with a dynamometer in a test cell. Test cycle and emissions measurement procedures were developed for evaluating the regulated and non-regulated gaseous emissions. Equipment and techniques for particulate matter measurements were adapted for use with the gasoline direct injection engine. The particulate matter emissions produced by the engine were compared between two different fuels; gasoline and E10 (10% ethanol and 90% gasoline). The gaseous emissions generated by the engine when it was run on gasoline and E30 (30% ethanol and 70% gasoline) were also compared. Particle number decreased with E10 for hot start conditions, while the opposite was observed for cold start conditions. Particulate matter emissions were found to track with acetylene and ethylene emissions.

A gasoline direct injection engine was set-up to operate with a dynamometer in a test cell. Test cycle and emissions measurement procedures were developed for evaluating the regulated and non-regulated gaseous emissions. Equipment and techniques for particulate matter measurements were adapted for use with the gasoline direct injection engine. The particulate matter emissions produced by the engine were compared between two different fuels; gasoline and E10 (10% ethanol and 90% gasoline). The gaseous emissions generated by the engine when it was run on gasoline and E30 (30% ethanol and 70% gasoline) were also compared. Particle number decreased with E10 for hot start conditions, while the opposite was observed for cold start conditions. Particulate matter emissions were found to track with acetylene and ethylene emissions.

No description available.

The aims and objectives: The aims and objectives of this study were to characterize and compare the airborne particulate matter in the tankhouse and crusher areas of a base metal refinery sampled with two separate methods, in terms of mass concentration, nickel content, and particle size distribution. Methods: Area sampling was conducted in the two areas. Two methods were applied to collect particulate samples. The first is a multi–stage virtual impactor, the Respicon, which was used to determine the three critical particle fractions (inhalable, thoracic and respirable). The NIOSH 7300 method determined the particle concentration and nickel percentage present in each fraction. Using formulas provided by the manufacturers two additional particle–size fractions (extra–thoracic and trachea–bronchial) could be calculated. The second was based on the standard NIOSH 0500 method, which determined particle size distribution depicted as cumulative percentages. The samples were analyzed using laser scattering instrumentation. Results: In the tankhouse the highest level of exposure was to particles bigger than 10 um, with the highest nickel percentage also falling into this range. However, high nickel percentages were present in all three cut–off sizes (4 um, 10 um and > 10 um). The particle concentration for the crusher area was the highest for particulates bigger than 10 um, with the highest nickel percentage present in this fraction. After comparing the tankhouse and crusher areas, it is clear that the particle concentration is much higher in the crusher area according to all sampling methods used. The nickel content present in the analysis of these areas is of great concern. Conclusion: With the knowledge obtained through this research one hopes to establish a basis for particle size sampling in the platinum mining industry. This may lead to the development of health based OEL's and reflect a more accurate evaluation of workers particulate exposure. This information will give a greater understanding of health risks workers are exposed to. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Background: Workers are daily exposed to diesel exhaust (DE) and DPM due to the continuous increase of diesel–powered vehicles in the underground mining environment. The National Institute for Occupational Safety and Health (NIOSH) recommends that DE be regarded as a “potential occupational carcinogen”. A great concern in the South African mining industry is that there is currently no existing occupational exposure limits (OEL) for DPM. Aim: To quantify the exposure of workers to DPM (that consists out of total carbon (TC): which is a combination of elemental carbon (EC) and organic carbon (OC)) in the ambient air of underground working environments. Also to compare different occupations exposure levels to an international standard (the Mine Safety and Health Administration’s (MSHA) OEL for TC) as South Africa has no proposed guideline or standard for occupational exposure to DPM and finally to determine whether or not occupations working at mines with different mining methods have different exposure levels to DPM. Methodology: Workers personal exposure to DPM was monitored using the NIOSH 5040 method. A DPM sampler that consisted of a cyclone, a pre–packed SKC filter cassette (37 mm) with impactor, tubing, label clips and a sampling pump was used. The flow rate was calibrated at 2.0 litres per minute (L/min) for the sampling of sub–micrometer particles. The personal sampler device was attached to the employee’s breathing zone for the duration of the work shift (normal eight–hour time–weighted average (TWA) standard). A high risk group (workers operating diesel–powered vehicles), a low risk group (workers working in the same mine, sharing the same supplied air, but not operating these vehicles) and a control group (workers working at a different mine with a different mining method) was monitored. The exposure levels were evaluated and compared with the specific OEL mentioned previously. Results: For the purpose of this study, TC exposure results were evaluated and not EC or OC. All the occupations within their specific exposure group was exposed to TC. When the control group’s exposures were compared with the high and low risk group exposures, a significant difference was recorded (p–value = 0.0001). However when the high and low risk exposures were compared with each other, no difference was recorded (p–value = 0.4405). When the results of the various groups were compared with the MSHA OEL all the occupations from the high and low risk group’s results were above the OEL, but only one occupation from the control group exceeded the OEL. Conclusion: It should be noted that all the occupations no matter the mining method / mine was exposed to TC. The high and low risk exposure groups was however much higher than the control group and a continues monitoring programme should be implemented for these exposure groups. Their results exceeded the OEL, where the control group had much lower exposure levels and only one occupation exceeded the OEL. Greater focus should be given to the mechanized mining occupations since diesel–powered vehicles are used to perform their core mining needs whereas at the conventional mine the use of these vehicles are limited. Recommendation: Depending on the different occupations sampled various engineering controls can be considered. Some include diesel oxidation catalysts (DOC), diesel particulate filters (DPF) and diesel disposable exhaust filters (DEF) or also known as disposable diesel exhaust filters (DDEF) which is very effective in removing DPM from the exhaust of dieselpowered equipment. Education and training are also critical components to the success of a diesel emission management programme and the last resort to be considered is the appropriate personal protective equipment (PPE). South Africa should consider the implementation of national standards in order to monitor the progress and success of the diesel emission management programme implemented. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2012.

The aims and objectives: The aims and objectives of this study were to characterize and compare the airborne particulate matter in the tankhouse and crusher areas of a base metal refinery sampled with two separate methods, in terms of mass concentration, nickel content, and particle size distribution. Methods: Area sampling was conducted in the two areas. Two methods were applied to collect particulate samples. The first is a multi–stage virtual impactor, the Respicon, which was used to determine the three critical particle fractions (inhalable, thoracic and respirable). The NIOSH 7300 method determined the particle concentration and nickel percentage present in each fraction. Using formulas provided by the manufacturers two additional particle–size fractions (extra–thoracic and trachea–bronchial) could be calculated. The second was based on the standard NIOSH 0500 method, which determined particle size distribution depicted as cumulative percentages. The samples were analyzed using laser scattering instrumentation. Results: In the tankhouse the highest level of exposure was to particles bigger than 10 um, with the highest nickel percentage also falling into this range. However, high nickel percentages were present in all three cut–off sizes (4 um, 10 um and > 10 um). The particle concentration for the crusher area was the highest for particulates bigger than 10 um, with the highest nickel percentage present in this fraction. After comparing the tankhouse and crusher areas, it is clear that the particle concentration is much higher in the crusher area according to all sampling methods used. The nickel content present in the analysis of these areas is of great concern. Conclusion: With the knowledge obtained through this research one hopes to establish a basis for particle size sampling in the platinum mining industry. This may lead to the development of health based OEL's and reflect a more accurate evaluation of workers particulate exposure. This information will give a greater understanding of health risks workers are exposed to. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Background: Workers are daily exposed to diesel exhaust (DE) and DPM due to the continuous increase of diesel–powered vehicles in the underground mining environment. The National Institute for Occupational Safety and Health (NIOSH) recommends that DE be regarded as a “potential occupational carcinogen”. A great concern in the South African mining industry is that there is currently no existing occupational exposure limits (OEL) for DPM. Aim: To quantify the exposure of workers to DPM (that consists out of total carbon (TC): which is a combination of elemental carbon (EC) and organic carbon (OC)) in the ambient air of underground working environments. Also to compare different occupations exposure levels to an international standard (the Mine Safety and Health Administration’s (MSHA) OEL for TC) as South Africa has no proposed guideline or standard for occupational exposure to DPM and finally to determine whether or not occupations working at mines with different mining methods have different exposure levels to DPM. Methodology: Workers personal exposure to DPM was monitored using the NIOSH 5040 method. A DPM sampler that consisted of a cyclone, a pre–packed SKC filter cassette (37 mm) with impactor, tubing, label clips and a sampling pump was used. The flow rate was calibrated at 2.0 litres per minute (L/min) for the sampling of sub–micrometer particles. The personal sampler device was attached to the employee’s breathing zone for the duration of the work shift (normal eight–hour time–weighted average (TWA) standard). A high risk group (workers operating diesel–powered vehicles), a low risk group (workers working in the same mine, sharing the same supplied air, but not operating these vehicles) and a control group (workers working at a different mine with a different mining method) was monitored. The exposure levels were evaluated and compared with the specific OEL mentioned previously. Results: For the purpose of this study, TC exposure results were evaluated and not EC or OC. All the occupations within their specific exposure group was exposed to TC. When the control group’s exposures were compared with the high and low risk group exposures, a significant difference was recorded (p–value = 0.0001). However when the high and low risk exposures were compared with each other, no difference was recorded (p–value = 0.4405). When the results of the various groups were compared with the MSHA OEL all the occupations from the high and low risk group’s results were above the OEL, but only one occupation from the control group exceeded the OEL. Conclusion: It should be noted that all the occupations no matter the mining method / mine was exposed to TC. The high and low risk exposure groups was however much higher than the control group and a continues monitoring programme should be implemented for these exposure groups. Their results exceeded the OEL, where the control group had much lower exposure levels and only one occupation exceeded the OEL. Greater focus should be given to the mechanized mining occupations since diesel–powered vehicles are used to perform their core mining needs whereas at the conventional mine the use of these vehicles are limited. Recommendation: Depending on the different occupations sampled various engineering controls can be considered. Some include diesel oxidation catalysts (DOC), diesel particulate filters (DPF) and diesel disposable exhaust filters (DEF) or also known as disposable diesel exhaust filters (DDEF) which is very effective in removing DPM from the exhaust of dieselpowered equipment. Education and training are also critical components to the success of a diesel emission management programme and the last resort to be considered is the appropriate personal protective equipment (PPE). South Africa should consider the implementation of national standards in order to monitor the progress and success of the diesel emission management programme implemented. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2012.